[Scintigraphy of myocardial perfusion combined with pharmacologic stress with dipyridamole]

To analyze adverse reactions (AR), hemodynamic and electrocardiographic changes and thallium scintigraphy (TS) results, during pharmacological stress with dipyridamole (SD), correlating these data to the presence and extension of coronary artery disease (CAD).

We studied 126 patients, 66 had no evidence of cardiovascular disease (G1) and 60 had critical occlusive CAD > or = 70% stenosis (G2). Most of them were male, mean age 56.5 +/- 10.9 years old. All patients were submitted to TS after receiving 0.56 mg/kg of dipyridamole intravenously (0.14 mg/min during 4 min) followed by 111MBq of thallium-chloride-201. Conventional ECG was recorded before and after SD; heart rate (HR) and arterial pressure (AP) were monitored during dipyridamole infusion. All signals and/or symptoms were observed.

Cine-coronarography showed 22 patients (37%) with one vessel disease (VD) (G2a), 26 (46%) with two VD (G2b) and 12 (20%) with three VD (G2c). Of the 126 patients 63% did not present symptoms. Flushing (25%) and sick-headache (12%) were most frequent AR. Typical angina was reported by one G1 patient (1.5%) and six G2 patients (10%) (p < 0.05). HR increased 18.09 +/- 12.27% and 12.40 +/- 4.90%, systolic blood pressure varied -5.2 +/- 7.5% and -4.3 +/- 6.5% in G1 and G2, respectively. These parameters are not correlated to CAD presence and extension. ST depression and ectopic beats occurred in 5% and 11% of G1 patients, in 15% and 30% of G2 patients, respectively (p < 0.05). Typical angina was more common in G2a and G2b; ST changes in G2b and G2c; and arrhythmia in G2c (not significant). Sensitivity of TS associated to SD was 84%, comparable to stress exercise thallium test.

TS associated to SD, a noninvasive, safe with low morbidity and few collateral effects method is an option to patients with limitations to physical exercise tests.